/*
 * The contents of this web application are subject to the Mozilla Public License Version 
 * 1.1 (the "License"); you may not use this web application except in compliance with 
 * the License. You may obtain a copy of the License at http://www.mozilla.org/MPL/.
 * 
 * Software distributed under the License is distributed on an "AS IS" basis, 
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License 
 * for the specific language governing rights and limitations under the License.
 * 
 * The Original Code is owned by and the Initial Developer of the Original Code is 
 * Composite A/S (Danish business reg.no. 21744409). All Rights Reserved
 * 
 * Section 11 of the License is EXPRESSLY amended to include a provision stating 
 * that any dispute, including but not limited to disputes related to the enforcement 
 * of the License, to which Composite A/S as owner of the Original Code, as Initial 
 * Developer or in any other role, becomes a part to shall be governed by Danish law 
 * and be initiated before the Copenhagen City Court ("K�benhavns Byret")            
 */

using System;
using System.Collections.Generic;
using System.Globalization;
using System.Linq;
using System.ServiceModel.Syndication;
using System.Web;
using System.Xml;
using Composite.Data;
using Composite.Data.Types;

namespace Composite.Community.Blog
{
    public class BlogRssFeed : IHttpHandler
    {
        public const string CacheRSSKeyTemplate = "BlogRssFeed-{0}-{1}";

        public void ProcessRequest(HttpContext context)
        {
            Guid pageId = Guid.Empty;

            if (context.Request["bid"] != null && Guid.TryParse(context.Request["bid"], out pageId))
            {
                bool isGlobal = Convert.ToBoolean(context.Request["IsGlobal"]);
                string cultureName = context.Request["cultureName"];
                if (string.IsNullOrEmpty(cultureName))
                {
                    cultureName = DataLocalizationFacade.DefaultLocalizationCulture.Name;
                }
                string cachedRssKey = string.Format(CacheRSSKeyTemplate, pageId, cultureName);
                if (context.Cache[cachedRssKey] == null)
                {
                    var cultureInfo = new CultureInfo(cultureName);
                    context.Response.ContentType = "text/xml";

                    using (var conn = new DataConnection(cultureInfo))
                    {
                        string pageUrl = BlogFacade.GetPageUrlById(pageId);
                        if (!string.IsNullOrEmpty(pageUrl))
                        {
                            pageUrl = BlogFacade.GetFullPath(pageUrl);
                            string pageTitle =
                                conn.Get<IPage>().Where(p => p.Id == pageId).Select(p => p.Title).Single();
                            var feed = new SyndicationFeed(pageTitle, "", new Uri(pageUrl));
                            var blogItems =
                                conn.Get<Entries>()
                                    .Where(b => isGlobal ? b.PageId != null : b.PageId == pageId)
                                    .Select(b => new {b.Id, b.Title, b.Date, b.Teaser, b.Tags, b.PageId})
                                    .OrderByDescending(b => b.Date)
                                    .ToList();

                            List<SyndicationItem> items = (from blog in blogItems
                                                           let blogUrl =
                                                               BlogFacade.GetBlogUrl(blog.Date, blog.Title, blog.PageId,
                                                                                     pageUrl)
                                                           select
                                                               new SyndicationItem(blog.Title, blog.Teaser,
                                                                                   new Uri(blogUrl), blog.Id.ToString(),
                                                                                   blog.Date)).ToList();

                            feed.Items = items;
                            context.Cache[cachedRssKey] = feed;
                        }
                    }
                }

                var syndicationFeed = (SyndicationFeed) context.Cache[cachedRssKey];

                using (XmlWriter writer = XmlWriter.Create(context.Response.OutputStream))
                {
                    syndicationFeed.SaveAsRss20(writer);
                }
            }
            else
            {
                context.Response.Write("The required query paramerer 'bid' (blog page GUID) is missing.");
            }
        }

        public bool IsReusable
        {
            get { return true; }
        }
    }
}